Drag items from the Data pane on the left and drop them into either the Measures or Dimensions groups in the Model pane in the center. The Measures and Dimensions groups will expand to include the items you drag into them.

Select each new measure and dimension item, and modify its details accordingly in the Properties pane on the right.

Save your model through the File menu, or publish it to the BA Server using the Publish icon above the Model pane.